1. Technical Field of the Invention
The present invention relates to a pressurizing device or dispenser comprising at least (A) a reservoir containing at least one composition intended for protecting the skin and/or the hair against ultraviolet radiation, said at least one composition which comprises, in a cosmetically acceptable aqueous carrier, at least: (a) a photoprotective system capable of screening out UV radiation; (b) generally spherical microparticles of porous silica; and (B) means which make it possible to put the at least one composition under pressure.
2. Description of Background/Related/Prior Art
It is known that light radiation having wavelengths of between 280 nm and 400 nm allows tanning of the human epidermis, and that radiation having wavelengths of between 280 nm and 320 nm, known by the name UV-B radiation, causes erythemas and skin burns which can impede the development of natural tanning; this UV-B radiation should therefore be screened out.
It is also known that UV-A rays having wavelengths of between 320 nm and 400 nm, which cause tanning of the skin, are capable of inducing its impairment, in particular in the case of a sensitive skin or of a skin continually exposed to solar radiation. UV-A rays cause in particular a loss of elasticity of the skin and the appearance of wrinkles which lead to premature skin aging. They promote the onset of the erythematous reaction or amplify this reaction in some subjects and may even be responsible for phototoxic or photoallergic reactions. It is therefore desirable also to screen out UV-A radiation.
Many cosmetic compositions intended for photoprotecting (UV-A and/or UV-B) the skin are known to this art.
These anti-sun compositions are quite often provided in the form of an oil-in-water type emulsion (that is to say a cosmetically acceptable carrier consisting of an aqueous dispersing continuous phase and an oily dispersed discontinuous phase) which contains, in various concentrations, one or more lipophilic and/or hydrophilic conventional organic screening agents capable of selectively absorbing harmful UV radiation, these screening agents (and their quantities) being selected according to the desired sun protection factor, the sun protection factor (SPF) mathematically expressing the ratio of the dose of UV radiation necessary to achieve the erythematogenic threshold with the UV screening agent to the dose of UV radiation necessary to achieve the erythematogenic threshold without UV screening agent.
Accordingly, an increasing need exists for anti-sun or sunscreen products having a high protection index. High protection indices can be obtained by incorporating more screening agents in high concentrations. This can not always be done since the addition of large quantities of screening agents considerably increases the cost of the anti-sun formulations and the risks of skin irritation.
Anti-sun/sunscreen products provided in spray form are increasingly sought by consumers because of their ease of use and their cosmetic pleasantness.
Unlike conventional anti-sun milks and creams, it is particularly difficult to obtain anti-sun compositions in spray form having a high protection index.